Add administrative room close and reopen controls

Preserve readable private tables, discussion and pending games while closure blocks new play, joins, messages, AI and seat mutations. Add live-authorized atomic closure audits, room-version/revision fences, dedicated controls and exact saved retries. Reopen with the saved pause/join settings and current credentials; restoring a removed but closed room keeps its AI stopped.

Verified types, lint, 5356 offline tests, 52 HTTP tests and build. Seventeen dedicated authenticated HTTP groups and independent privacy/persistence review passed. Desktop/mobile browser QA confirmed one close after a lost response and refresh, persistent readable notices, retained private draft, mobile reopening and saved-seat refresh. All 2,001 baseline rooms, 4,243 seats and related records preserved. Positive production admin acceptance awaits authorized QA access; full admin and rules gates remain open.

drizzle/meta/_journal.json

@@ -92,6 +92,13 @@
       "when": 1790040786205,
       "tag": "0012_admin_room_removal",
       "breakpoints": true
+    },
+    {
+      "idx": 13,
+      "version": "6",
+      "when": 1790042692212,
+      "tag": "0013_admin_room_closure",
+      "breakpoints": true
     }
   ]
 }